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Finding the Fourth Proportional to 77.40, 115.92 and 41.28

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Solution

The fourth proportional to 77.40, 115.92 and 41.28 is: 61.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.40 : 115.92 = 41.28 : x
  2. Step 2: Convert to fraction form
    77.40/115.92 = 41.28/x
  3. Step 3: Cross multiply
    77.40x = 115.92 × 41.28
  4. Step 4: Simplify right side
    77.40x = 4,785.18
  5. Step 5: Solve for x
    x = 4,785.18/77.40
  6. Step 6: Final answer
    x = 61.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.